JP6072277B2 - Engine system with intake bypass device - Google Patents

Description

  The present disclosure relates to an engine system including an intake bypass device that guides a part of compressed intake air compressed by a compressor to bypass an engine body and upstream of an exhaust turbine.

  As a technique for improving engine output, a method (supercharging) in which intake air is compressed by a turbocharger and the compressed intake air is supplied to the engine is known and widely used in automobile engines and the like. Particularly in recent years, supercharging has been performed in a wide operating range from a low output range to a high output range against the backdrop of stricter exhaust gas and fuel efficiency regulations.

  On the other hand, a turbocharger may transiently generate surging depending on its operating state. The occurrence of surging in a turbocharger must be prevented as much as possible because it may lead to damage to equipment such as an impeller. For this reason, there is a demand for a technique for expanding the operating range of the compressor as much as possible while avoiding the occurrence of surging.

As a technique for expanding the operating range of the compressor while avoiding the occurrence of surging, for example, as disclosed in Patent Document 1, a part of the compressed intake air compressed by the compressor is bypassed the engine body and the exhaust turbine An intake bypass device that conducts upstream is known.
The intake bypass device of Patent Document 1 includes a bypass passage that connects a downstream of the compressor in the intake passage and an upstream of the exhaust turbine in the exhaust passage, and a flow rate adjusting valve provided in the bypass passage. The flow rate adjusting valve is controlled so that the valve opening becomes large when the operating point of the compressor enters the vicinity of the surge region. As the valve opening of the flow rate adjustment valve increases, the flow rate of the compressed intake air that is introduced upstream of the exhaust turbine via the bypass passage increases. As a result, turbine output is increased, and surging is prevented by increasing the operating flow rate of the compressor.

JP 2000-64844 A

  However, in the intake bypass device of Patent Document 1 described above, the relatively low-temperature compressed intake air merges with the high-temperature exhaust gas discharged from the engine, and the exhaust turbine is driven by the exhaust gas after the compressed air merges. . For this reason, the energy of the exhaust gas which drives an exhaust turbine falls, and there existed a problem that the output of an exhaust turbine was insufficient.

  At least one embodiment of the present invention has been made in view of the conventional problems as described above. The object of the present invention is to expand the operating range of the compressor and to increase the output of the exhaust turbine. It is an object of the present invention to provide an engine system including an intake bypass device that does not run short.

At least one embodiment of the present invention provides:
In an engine system equipped with an intake bypass device,
The engine system includes:
An engine body, an intake passage for supplying intake air to the engine body, an exhaust passage for flowing exhaust gas discharged from the engine body,
A turbocharger comprising: an exhaust turbine disposed in the exhaust passage that is driven by energy of exhaust gas discharged from the engine body; and a compressor disposed in the intake passage that is coaxially driven with the exhaust turbine;
An intake bypass device for guiding a part of the compressed intake air compressed by the compressor to the upstream of the exhaust turbine, bypassing the engine body,
The intake bypass device is
A bypass passage connecting a downstream of the compressor in the intake passage and an upstream of the exhaust turbine in the exhaust passage;
A bypass valve disposed in the bypass passage for controlling the flow of the compressed intake air in the bypass passage;
Heating means for heating the compressed intake air flowing through the bypass passage.

  According to the engine system including the intake bypass device, the intake bypass device includes heating means for heating the compressed intake air flowing through the bypass passage, and the heated compressed intake air is introduced upstream of the exhaust turbine. It is configured as follows. For this reason, the fall of the energy of the exhaust gas which drives an exhaust turbine can be prevented, and it can prevent that the output of an exhaust turbine runs short.

  In some embodiments, the heating means is configured to utilize the exhaust gas discharged from the engine body as a heat source for heating the compressed intake air flowing through the bypass passage.

  According to such an embodiment, the compressed intake air flowing through the bypass passage can be heated by effectively using the thermal energy of the exhaust gas discharged from the engine body without providing a separate heat source such as a heater.

  In some embodiments, the heating means is configured such that the turbine housing of the exhaust turbine forms at least a part of the inner wall surface of the bypass passage in a partial section of the bypass passage.

  According to such an embodiment, the compressed intake air flowing through the bypass passage can be heated by the thermal energy of the exhaust gas flowing through the turbine housing. In addition, since the turbine housing can be cooled by the compressed intake air flowing through the bypass passage, it is not necessary to use an expensive heat-resistant material for the turbine housing, and the cost can be reduced.

  In the above-described embodiment, at least a part of the turbine housing has a double structure including an inner housing made of sheet metal and an outer housing made of sheet metal that covers the inner housing. A space defined by the inner housing and the outer housing forms a partial section of the bypass passage in the embodiment.

  According to such an embodiment, the space defined by the inner housing and the outer housing is used as a partial section of the bypass passage in the above embodiment, and the compressed intake air is heated and the turbine housing is caused to flow through this space. Can be efficiently cooled.

  In some embodiments, the engine system further includes an exhaust gas purification device for purifying exhaust gas exhausted from the engine body. This exhaust gas purification device is disposed downstream of the exhaust turbine in the exhaust passage. The heating means is configured such that, in a partial section of the bypass passage, the exhaust passage downstream of the exhaust gas purification device forms at least a part of the inner wall surface of the bypass passage.

  According to such an embodiment, the compressed intake air flowing through the bypass passage can be heated by the thermal energy of the exhaust gas flowing through the exhaust passage. In addition, the exhaust gas after driving the exhaust turbine and passing through the exhaust gas purification device to heat the catalyst is recovered, which affects the output of the exhaust turbine and the purification performance of the exhaust gas purification device. The compressed intake air can be heated without giving

  In the above embodiment, at least a part of the exhaust passage downstream of the exhaust gas purification device has a double structure consisting of an inner exhaust pipe through which exhaust gas flows and an outer exhaust pipe covering the inner exhaust pipe. There is no. A space defined by the inner exhaust pipe and the outer exhaust pipe forms a partial section of the bypass passage in the embodiment.

  According to such an embodiment, the space defined by the inner exhaust pipe and the outer exhaust pipe is set as a partial section of the bypass passage in the above-described embodiment, and the compressed intake air is efficiently supplied by flowing the compressed intake air into this space. Can be heated.

  In some embodiments, the heating means is configured such that an exhaust manifold connecting the engine body and the exhaust passage forms at least a part of the inner wall surface of the bypass passage in a partial section of the bypass passage.

  According to such an embodiment, the compressed intake air flowing through the bypass passage can be heated by the thermal energy of the exhaust gas flowing through the exhaust manifold. In addition, by exchanging heat with the high-temperature exhaust gas flowing through the exhaust manifold, it is not necessary to use an expensive heat-resistant material in the exhaust manifold and the exhaust passage downstream of the exhaust manifold, and the cost can be reduced.

  In the above embodiment, at least a part of the exhaust manifold has a double structure including an inner exhaust manifold through which exhaust gas flows and an outer exhaust manifold that covers the inner exhaust manifold. A space defined by the inner exhaust manifold and the outer exhaust manifold forms a partial section of the bypass passage in the embodiment.

  According to such an embodiment, the space defined by the inner exhaust manifold and the outer exhaust manifold is a partial section of the bypass passage in the above embodiment, and the compressed intake air is heated by flowing the compressed intake air into this space. The exhaust manifold can be cooled efficiently.

  In some embodiments, the intake bypass device includes a turbo control unit having a control unit and a signal input unit that are independent from the engine control unit that controls the operating state of the engine body. The turbo control unit includes a bypass valve control unit that controls the valve opening degree of the bypass valve.

With the recent sophistication of engines, the control logic and hardware configuration of engine controllers are becoming increasingly complex. For this reason, when a bypass valve control unit for controlling the valve opening degree of the bypass valve is mounted on the engine controller, the control logic and hardware configuration of the engine controller become more complicated. In addition, when a transient phenomenon such as surging is controlled by an engine controller having a complicated control logic or hardware configuration, the communication delay may become a problem.
Therefore, as in the present embodiment, the engine control unit can be prevented from becoming complicated by mounting the bypass valve control unit in a turbo control unit configured separately from the engine control unit.

  In the above-described embodiment, the turbo control unit includes a turbo signal input unit to which sensor signals regarding various engine operating states such as a supercharging pressure, an intake air flow rate, an engine speed, and a turbo speed are input, and the turbo signal input unit. An operating point calculation unit that calculates an operating point of the compressor based on the sensor signal input to the turbocharger, and a turbo control unit including the bypass valve control unit. The bypass valve control unit is configured to control the valve opening of the bypass valve to be large when the operating point calculated by the operating point calculation unit is in the vicinity of the surge region.

  According to such an embodiment, since the turbo control unit itself calculates the operating point of the compressor and controls the valve opening of the bypass valve based on the calculated operating point, the valve opening of the bypass valve is controlled by the engine control unit. As compared with the case of controlling the bypass valve, the bypass valve can be controlled quickly while avoiding the influence of communication delay.

  In the above embodiment, the sensor signal is composed of a sensor signal related to the supercharging pressure of compressed air compressed by the compressor and the intake air flow rate flowing through the compressor.

  According to such an embodiment, the operating point of the compressor can be accurately calculated from the supercharging pressure and the intake air flow rate.

  According to at least one embodiment of the present invention, there is provided a DPF regeneration control device capable of preventing DOC blockage more efficiently than in the prior art and reliably recovering from the blockage state even when the DOC is actually blocked. I can do it.

1 is an overall configuration diagram showing an engine system including an intake bypass device according to a first embodiment of the present invention. It is the compressor map which showed the operating characteristic of the compressor. It is a block diagram for demonstrating the function of turbo ECU. It is the whole block diagram which showed the engine system provided with the intake bypass device concerning 2nd Embodiment of this invention. It is the schematic sectional drawing which showed an example of the heating means of 2nd Embodiment. It is the schematic sectional drawing which showed the other example of the heating means of 2nd Embodiment. It is a whole lineblock diagram showing an engine system provided with an intake bypass device concerning a 3rd embodiment of the present invention. It is the schematic sectional drawing which showed an example of the heating means of 3rd Embodiment. It is the schematic sectional drawing which showed the other example of the heating means of 3rd Embodiment. It is a whole block diagram which showed the engine system provided with the intake bypass device concerning 4th Embodiment of this invention. It is the schematic sectional drawing which showed an example of the heating means of 4th Embodiment. It is the schematic sectional drawing which showed the other example of the heating means of 4th Embodiment.

Hereinafter, embodiments of the present invention will be described in more detail based on the drawings.
However, the scope of the present invention is not limited to the following embodiments. The dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the following embodiments are not merely intended to limit the scope of the present invention, but are merely illustrative examples.

<First Embodiment>
FIG. 1 is an overall configuration diagram showing an engine system provided with an intake bypass device according to a first embodiment of the present invention.
As shown in FIG. 1, the engine system 1 of the present embodiment is exhausted from an engine body 2, an intake passage 4 for supplying intake air to a cylinder 2 a of the engine body 2, and a cylinder 2 a of the engine body 2. An exhaust passage 6 for flowing exhaust gas, a turbocharger 12 for compressing intake air supplied to the engine body 2, and a part of the compressed intake air compressed by the turbocharger 12 bypassing the engine body 2 and exhausted. And an intake bypass device 20 for conducting the air to the passage 6.

  The engine body 2 includes a plurality of cylinders 2a. The engine body 2 and the intake passage 4 are connected via an intake manifold 5, and the intake manifold 5 distributes the intake air flowing through the intake passage 4 to each of the plurality of cylinders 2a. The engine body 2 and the exhaust passage 6 are connected via an exhaust manifold 7, and exhaust gas discharged from the plurality of cylinders 2 a is collected in the exhaust passage 6 by the exhaust manifold 7. .

  The turbocharger 12 includes an exhaust turbine 8 disposed in the exhaust passage 6 and a compressor 10 disposed in the intake passage 4 that is connected to the exhaust turbine 8 by a rotor and is driven coaxially therewith. The exhaust turbine 8 is driven by the exhaust energy of the exhaust gas discharged from the engine body 2, whereby the compressor 10 is coaxially driven to compress the intake air flowing through the intake passage 4.

  An air flow meter 31 for measuring the intake air flow rate is disposed upstream of the compressor 10 in the intake passage 4. Further, a pressure sensor 33 for measuring the supercharging pressure of the compressed intake air is disposed downstream of the compressor 10 in the intake passage 4.

  The intake bypass device 20 includes a bypass passage 14 connecting the downstream of the compressor 10 in the intake passage 4 and the upstream of the exhaust turbine 8 in the exhaust passage 6, a bypass valve 16 disposed in the bypass passage 14, and the bypass passage 14. It comprises heating means 18 for heating the flowing compressed intake air.

  The bypass valve 16 of the present embodiment is configured as a flow control valve for controlling the flow rate of the compressed intake air that is introduced from the intake passage 4 to the exhaust passage 6. The valve opening degree of the bypass valve 16 is controlled by a turbo ECU (turbo control unit) 24 described later so that surging does not occur in the compressor 10. In the present invention, the type of the bypass valve 16 is not limited to the flow control valve. It is sufficient that at least the backflow of the exhaust gas from the exhaust passage 6 to the intake passage 4 can be prevented. For example, a check valve may be used.

FIG. 2 is a compressor map showing the operating characteristics of the compressor. In the figure, the horizontal axis represents the flow rate, and the vertical axis represents the pressure ratio between the inlet and the outlet of the compressor 10. Reference numerals N1, N2, and N3 in the figure indicate compressor rotation speeds.
As shown in FIG. 2, when the compressor 10 operates at a low flow rate and a high pressure ratio, the operating point P1 may shift to the left side of the surge line and enter the surge region. When the operating point (operating line) of the compressor 10 enters the surge region, surging occurs in the compressor 10. Therefore, when the operating point (operating line) of the compressor 10 is in the vicinity of the surge region, the valve opening degree of the bypass valve 16 is controlled to be increased, and the flow rate of the compressed intake air introduced from the intake passage 4 to the exhaust passage 6 is controlled. increase. As a result, the turbine output increases and the operating flow rate of the compressor 10 increases (Q1 → Q2), so that the operating point P2 deviates from the surge region. In this way, surging is prevented.

FIG. 3 is a block diagram for explaining the function of the turbo ECU.
The turbo ECU 24 is a control unit that is independent of the engine ECU 22 and has a control unit 24B and a signal input unit 24A that are independent from the engine ECU (engine control unit) 22 that controls the operating state of the engine body 2. The turbo ECU 24 and the engine ECU 22 are configured as a microcomputer including a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), an I / O interface, and the like.

  As shown in FIG. 3, the turbo ECU 24 includes a signal input unit 24A, a turbo control unit 24B, and a signal output unit 24C. Signals related to the intake air flow rate measured by the air flow meter 31 and the supercharging pressure measured by the pressure sensor 33 are input to the signal input unit 24A. The turbo control unit 24B includes an operating point calculation unit 24B1 and a bypass valve control unit 24B2. The operating point calculator 24B1 calculates the operating point of the compressor 10 from the compressor map shown in FIG. 2 from the intake air flow rate and the supercharging pressure input to the signal input unit 24A. The bypass valve controller 24B2 generates a bypass valve opening command value that increases the valve opening of the bypass valve 16 when the operating point calculated by the operating point calculator 24B1 is in the vicinity of the surge region. A signal relating to the generated bypass valve opening command value is output from the signal output unit 24C to the bypass valve 16, and thereby the valve opening of the bypass valve 16 is controlled.

With the recent sophistication of engines, the control logic and hardware configuration of the engine ECU 22 are becoming increasingly complex. For this reason, when the bypass valve control unit 24B2 for controlling the valve opening degree of the bypass valve 16 is mounted on the engine ECU 22, the control logic and hardware configuration of the engine ECU 22 become more complicated. Further, when a transient phenomenon such as surging is controlled by an engine ECU having a complicated control logic or hardware configuration, the communication delay may be a problem.
Therefore, as in the present embodiment, by installing the bypass valve control unit 24B2 in the turbo ECU 24 that is configured separately from the engine ECU 22, it is possible to prevent the engine ECU 22 from becoming complicated. Further, since the turbo ECU 24 itself calculates the operating point of the compressor 10 and controls the valve opening degree of the bypass valve 16 based on the calculated operating point, compared with the case where the engine ECU 22 controls the valve opening degree of the bypass valve 16. Thus, the bypass valve 16 can be quickly controlled while avoiding the influence of communication delay.

  The heating means 18 is for heating the compressed intake air flowing through the bypass passage 14. As the heating means 18, for example, a heater or the like may be provided and used as a heat source, and exhaust gas discharged from the engine body 2 may be used as a heat source as in an embodiment described later.

  According to the engine system 1 including such an intake bypass device 20, the intake bypass device 20 includes the heating means 18 for heating the compressed intake air flowing through the bypass passage 14 and is heated upstream of the exhaust turbine 8. The compressed intake air is guided. For this reason, it is possible to prevent the energy of the exhaust gas that drives the exhaust turbine 8 from being lowered, and to prevent the output of the exhaust turbine 8 from being insufficient.

Second Embodiment
FIG. 4 is an overall configuration diagram showing an engine system provided with an intake bypass device according to a second embodiment of the present invention. The engine system 1a of the present embodiment basically has the same configuration as the engine system 1 of the above-described embodiment except for the heating means 18 described above. Accordingly, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 5 is a schematic cross-sectional view showing an example of the heating means of the second embodiment. The heating means 18 of the embodiment shown in FIG. 5 is configured such that the turbine housing 8 </ b> A of the exhaust turbine 8 forms at least a part of the inner wall surface of the bypass passage 14 in a partial section of the bypass passage 14.

  In the embodiment shown in FIG. 5A, in the turbine housing 8A, a part of the outer wall surface of the scroll portion 8a forming the scroll flow path 8d forms a part of the inner wall surface of the bypass passage 14. A part of the outer wall surface of the scroll portion 8a indicated by reference numeral 14a in this figure corresponds to the heating means 18 of the present embodiment. Further, in the embodiment shown in FIG. 5B, the bypass passage 14 is configured by a through-hole formed in the shroud portion 8e of the turbine housing 8A, and the shroud portion 8e of the turbine housing 8A is bypassed. The inner wall surface of the passage 14 is formed. The entire inner wall surface indicated by reference numeral 14a in this figure corresponds to the heating means 18 of the present embodiment. In the figure, reference numeral 8b denotes a hub, 8c denotes an impeller, and 9 denotes a bearing housing.

  According to such an embodiment, since the compressed intake air flowing through the bypass passage 14 can be heated by the thermal energy of the exhaust gas flowing in the turbine housing 8A, a decrease in the energy of the exhaust gas that drives the exhaust turbine 8 is prevented. In addition, the shortage of the output of the exhaust turbine 8 can be avoided. Moreover, since the turbine housing 8A can be cooled by the compressed intake air flowing through the bypass passage 14, it is not necessary to use an expensive heat-resistant material for the turbine housing 8A, and the cost can be reduced.

  FIG. 6 is a schematic cross-sectional view showing another example of the heating means of the second embodiment. In the embodiment shown in FIG. 6, a part of the turbine housing 8A has a double structure including a sheet metal inner housing 8A1 that forms the scroll flow path 8d and a sheet metal outer housing 8A2 that covers the inner housing 8A1. There is no. A space defined by the inner housing 8A1 and the outer housing 8A2 forms a partial section of the bypass passage 14 described above. That is, the outer wall surface of the inner housing 8A1 forms a part of the inner wall surface of the bypass passage 14, and the outer wall surface (the portion indicated by reference numeral 14a in the drawing) of the inner housing 8A1 serves as the heating means 18 of the present embodiment. Equivalent to.

  According to such an embodiment, the space defined by the inner housing 8A1 and the outer housing 8A2 is set as a partial section of the bypass passage 14 described above, and the compressed intake air is heated and turbine is caused to flow through this space. The housing 8A can be efficiently cooled.

<Third Embodiment>
FIG. 7 is an overall configuration diagram showing an engine system provided with an intake bypass device according to a third embodiment of the present invention. The engine system 1b of the present embodiment further includes an exhaust gas purifying device 26 for purifying exhaust gas discharged from the engine body 2. The exhaust gas purification device 26 is disposed downstream of the exhaust turbine 8 in the exhaust passage 6. The heating means 18 described above is disposed downstream of the exhaust gas purification device 26. The engine system 1b of the present embodiment has the same configuration as that of the above-described embodiment, and the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 8 is a schematic cross-sectional view showing an example of the heating means of the third embodiment. In the heating unit 18 of the embodiment shown in FIG. 8, in a partial section of the bypass passage 14, a part of the outer surface of the exhaust pipe 6 a of the exhaust passage 6 downstream from the exhaust gas purification device 26 is the inner wall surface of the bypass passage 14. It is composed by making a part of. A part of the outer surface of the exhaust pipe 6a indicated by reference numeral 14a in this figure corresponds to the heating means 18 of the present embodiment.

  According to such an embodiment, since the compressed intake air flowing through the bypass passage 14 can be heated by the thermal energy of the exhaust gas flowing through the exhaust passage 6, it is possible to prevent a decrease in the energy of the exhaust gas that drives the exhaust turbine 8. In addition, the shortage of the output of the exhaust turbine 8 can be avoided. Moreover, in order to recover the excess heat energy of the exhaust gas after driving the exhaust turbine 8 and passing through the exhaust gas purification device 26 and heating the catalyst, the output of the exhaust turbine 8 and the exhaust gas purification device 26 The compressed intake air can be heated without affecting the purification performance.

  FIG. 9 is a schematic cross-sectional view showing another example of the heating means of the third embodiment. In the embodiment shown in FIG. 9, at least a part of the exhaust passage 6 on the downstream side of the exhaust gas purification device 26 includes an inner exhaust pipe 6b through which exhaust gas flows and an outer exhaust pipe 6c that covers the inner exhaust pipe. It has a double structure consisting of A space defined by the inner exhaust pipe 6b and the outer exhaust pipe 6c forms a partial section of the bypass passage 14 described above. That is, the outer surface of the inner exhaust pipe 6b forms a part of the inner wall surface of the bypass passage 14, and the outer surface of the inner exhaust pipe 6b (the part indicated by reference numeral 14a in the drawing) serves as the heating means 18 of the present embodiment. Equivalent to.

  According to such an embodiment, the space defined by the inner exhaust pipe 6b and the outer exhaust pipe 6c is defined as a partial section of the bypass passage described above, and the compressed intake air is efficiently supplied by flowing the compressed intake air into this space. It can be heated.

<Fourth embodiment>
FIG. 10 is an overall configuration diagram showing an engine system including an intake bypass device according to a fourth embodiment of the present invention. The engine system 1c of the present embodiment has basically the same configuration as the engine system 1 of the above-described embodiment except for the heating means 18 described above. Accordingly, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 11 is a schematic cross-sectional view showing an example of the heating means of the fourth embodiment. The heating means 18 of the embodiment shown in FIG. 11 is configured such that a part of the outer wall surface of the exhaust manifold 7 forms a part of the inner wall surface of the bypass passage 14 in a part of the bypass passage 14. A part of the outer wall surface of the exhaust manifold 7 indicated by reference numeral 14a in this figure corresponds to the heating means 18 of the present embodiment.

  According to such an embodiment, since the compressed intake air flowing through the bypass passage 14 can be heated by the thermal energy of the exhaust gas flowing in the exhaust manifold 7, the reduction in the energy of the exhaust gas that drives the exhaust turbine 8 is prevented. In addition, the shortage of the output of the exhaust turbine 8 can be avoided. In addition, by exchanging heat with the high-temperature exhaust gas flowing through the exhaust manifold 7, it is not necessary to use an expensive heat-resistant material for the exhaust manifold 7 and the exhaust passage 6 downstream of the exhaust manifold 7, thereby reducing costs. It can be done.

  FIG. 12 is a schematic sectional view showing another example of the heating means of the fourth embodiment. In the embodiment shown in FIG. 12, at least a part of the exhaust manifold 7 has a double structure including an inner exhaust manifold 7a through which exhaust gas flows inside and an outer exhaust manifold 7b covering the inner exhaust manifold 7a. A space defined by the inner exhaust manifold 7a and the outer exhaust manifold 7b forms a partial section of the bypass passage 14 described above. That is, the outer surface of the inner exhaust manifold 7a forms part of the inner wall surface of the bypass passage 14, and the outer surface of the inner exhaust manifold 7a (the portion indicated by reference numeral 14a in the drawing) serves as the heating means 18 of the present embodiment. Equivalent to.

  According to such an embodiment, the space defined by the inner exhaust manifold 7a and the outer exhaust manifold 7b is defined as a partial section of the bypass passage 14, and the compressed intake air is heated by flowing the compressed intake air into this space. And the exhaust manifold 7 can be efficiently cooled.

  As mentioned above, although the preferable form of this invention was demonstrated, this invention is not limited to said form. For example, the above-described embodiments may be combined, and various modifications can be made without departing from the object of the present invention.

  At least one embodiment of the present invention can be suitably used not only for automobiles but also for marine and industrial engines in an engine equipped with a turbocharger.

1, 1a to 1c Engine system 2 Engine body 2a Cylinder 4 Intake passage 5 Intake manifold 6 Exhaust passage 6a Exhaust pipe 6b Inner exhaust pipe 6c Outer exhaust pipe 7 Exhaust manifold 7a Inner exhaust manifold 7b Outer exhaust manifold 8 Exhaust turbine 8A Turbine housing 8A1 Inner housing 8A2 Outer housing 8a Scroll part 8b Hub 8c Impeller 8d Scroll channel 8e Shroud part 9 Bearing housing 10 Compressor 12 Turbocharger 14 Bypass passage 16 Bypass valve,
18 Heating means 20 Intake bypass device 22 Engine ECU
24 Turbo ECU
26 Exhaust gas purification device 31 Air flow meter 33 Pressure sensor

Claims (11)

In an engine system equipped with an intake bypass device,
The engine system includes:
An engine body, an intake passage for supplying intake air to the engine body, an exhaust passage for flowing exhaust gas discharged from the engine body,
A turbocharger comprising: an exhaust turbine disposed in the exhaust passage that is driven by energy of exhaust gas discharged from the engine body; and a compressor disposed in the intake passage that is coaxially driven with the exhaust turbine;
An intake bypass device for guiding a part of the compressed intake air compressed by the compressor to the upstream of the exhaust turbine, bypassing the engine body,
The intake bypass device is
A bypass passage connecting a downstream of the compressor in the intake passage and an upstream of the exhaust turbine in the exhaust passage;
A bypass valve disposed in the bypass passage for controlling the flow of the compressed intake air in the bypass passage;
A heating means disposed on the downstream side of the bypass valve in the bypass passage for heating the compressed intake air flowing through the bypass passage;
The heating means is configured to use exhaust gas discharged from the engine body as a heat source for heating the compressed intake air flowing through the bypass passage.
An engine system with an intake bypass device. The exhaust gas used as the heat source is an exhaust gas other than EGR gas that flows through an EGR passage for recirculating exhaust gas discharged from the engine body to the engine body.
An engine system comprising the intake bypass device according to claim 1. The heating means is configured such that a turbine housing of the exhaust turbine forms at least a part of an inner wall surface of the bypass passage in a partial section of the bypass passage.
An engine system comprising the intake bypass device according to claim 1. At least a part of the turbine housing has a double structure including an inner housing made of sheet metal and an outer housing made of sheet metal covering the inner housing, and a space defined by the inner housing and the outer housing is It is part of the bypass passage,
An engine system comprising the intake bypass device according to claim 3. The engine system further includes an exhaust gas purification device for purifying exhaust gas exhausted from the engine body, and the exhaust gas purification device is disposed downstream of the exhaust turbine in the exhaust passage;
The heating means is configured such that, in a partial section of the bypass passage, the exhaust passage downstream of the exhaust gas purification device forms at least a part of the inner wall surface of the bypass passage.
An engine system comprising the intake bypass device according to claim 1. At least a part of the exhaust passage downstream of the exhaust gas purification device has a double structure consisting of an inner exhaust pipe through which exhaust gas flows and an outer exhaust pipe covering the inner exhaust pipe. A space defined by the exhaust pipe and the outer exhaust pipe forms a partial section of the bypass passage;
An engine system comprising the intake bypass device according to claim 5. The heating means is configured such that, in a partial section of the bypass passage, an exhaust manifold that connects the engine body and the exhaust passage forms at least a part of an inner wall surface of the bypass passage.
An engine system comprising the intake bypass device according to claim 1. At least a part of the exhaust manifold has a double structure consisting of an inner exhaust manifold through which exhaust gas flows inside and an outer exhaust manifold that covers the inner exhaust manifold, and is defined by the inner exhaust manifold and the outer exhaust manifold. A space is part of the bypass passage,
An engine system comprising the intake bypass device according to claim 7. The intake bypass device includes a turbo control unit having a control unit and a signal input unit independent of an engine control unit that controls the operating state of the engine body, and the turbo control unit opens the bypass valve. Including a bypass valve controller to control the degree,
An engine system comprising the intake bypass device according to claim 1. The turbo control unit is
A turbo signal input unit to which a sensor signal related to the engine operating state is input;
An operating point calculation unit that calculates an operating point of the compressor based on a sensor signal input to the turbo signal input unit, and a turbo control unit including the bypass valve control unit,
The bypass valve control unit is configured to control the valve opening of the bypass valve to be large when the operating point calculated by the operating point calculation unit is in the vicinity of a surge region.
An engine system comprising the intake bypass device according to claim 9. The sensor signal is composed of a sensor signal related to a supercharging pressure of compressed intake air compressed by the compressor and an intake air flow rate flowing to the compressor.
An engine system comprising the intake bypass device according to claim 10.

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